CN107797023A - Imbalance of three-phase voltage source localization method, device and system - Google Patents
Imbalance of three-phase voltage source localization method, device and system Download PDFInfo
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- CN107797023A CN107797023A CN201610719964.0A CN201610719964A CN107797023A CN 107797023 A CN107797023 A CN 107797023A CN 201610719964 A CN201610719964 A CN 201610719964A CN 107797023 A CN107797023 A CN 107797023A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
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Abstract
The embodiment provides a kind of imbalance of three-phase voltage source localization method, device and system.Imbalance of three-phase voltage source localization method includes：Obtain voltage unbalance factor caused by the negative sequence voltage of points of common connection；If the voltage unbalance factor exceedes voltage unbalance factor limit value, voltage unbalance factor caused by the negative-sequence current of points of common connection is obtained；Imbalance of three-phase voltage source is positioned according to voltage unbalance factor caused by voltage unbalance factor caused by the negative sequence voltage and the negative-sequence current.Using the technical scheme of the embodiment of the present invention, imbalance of three-phase voltage can be occurred with accurate judgement points of common connection, and quickly uneven source is positioned, reduce the difficulty of test of imbalance of three-phase voltage, help quickly to eliminate imbalance of three-phase voltage, ensure power system stability operation.
Description
Technical field
The present invention relates to electric power network technique field, more particularly to a kind of imbalance of three-phase voltage source localization method, device and it is
System.
Background technology
Three-phase imbalance refers to that three-phase voltage (or three-phase current) amplitude in power system is inconsistent, and amplitude exceedes rule
Determine scope.The imbalance of three-phase voltage of power system can cause the electric energy loss increase of transmission line of electricity, distribution transformer, influence to use
The safe operation of electric equipment, the safe and stable operation to system bring hidden danger.
Power system may cause the unbalanced reason of Three-phase Power Systems to be summarized as：Fault uneven and non-faulting
Property it is uneven.Wherein, fault imbalance refers to Voltage unbalance caused by power system component failure, for example, power transmission sequence
Imbalance of three-phase voltage caused by Voltage Drop caused by single-phase or line to line fault.The unbalanced influence factor of non-faulting includes
Transmission line of electricity three-phase impedance unbalance, load unbalanced, mains side imbalance of three-phase voltage and voltage waveform distortion etc..For example,
New energy power station (wind power station or photo-voltaic power generation station etc.) points of common connection is mostly power network end, and its regional power grid belongs to voltage
The light current net of stability difference, the quality of power supply of points of common connection is easily influenceed after power system is accessed, is especially being incorporated into the power networks
Early stage, easily produce the imbalance of three-phase voltage of points of common connection.
At present, the research on imbalance of three-phase voltage in the prior art, mainly for how uneven using three-phase voltage
The characteristic of weighing apparatus is protected to power system, and how to eliminate imbalance of three-phase voltage etc., how effectively quick but have ignored
The problem of judging imbalance of three-phase voltage source orientation., can also be according to the fortune of each electrical equipment for fault three-phase imbalance
Row state determines uneven source, and three-phase imbalance is eliminated by cutting off failure.But for non-faulting imbalance of three-phase voltage,
Staff rule of thumb can only be carried out substantial amounts of test checking in diverse location and search reason, can not but judged in time
The orientation in uneven source, and need to expend a large amount of manpower and materials, and lose time, make system long-play in imbalance
State, cause the quality of power supply to decline, influence power system device safety, jeopardize stability of power system and security reliability.
The content of the invention
Embodiments of the invention provide a kind of imbalance of three-phase voltage source localization method, device and system, with fast positioning
Imbalance of three-phase voltage source, it is convenient to carry out malfunction elimination and eliminate imbalance of three-phase voltage, it is favorably improved the steady of power system
It is qualitative.
To reach above-mentioned purpose, the embodiment provides a kind of imbalance of three-phase voltage source localization method, including：
Obtain voltage unbalance factor caused by the negative sequence voltage of points of common connection；If the voltage unbalance factor exceedes Voltage unbalance
Limit value is spent, then obtains voltage unbalance factor caused by the negative-sequence current of points of common connection；It is electric according to caused by the negative sequence voltage
Voltage unbalance factor caused by pressure degree of unbalancedness and the negative-sequence current positions to imbalance of three-phase voltage source.
Alternatively, voltage caused by the voltage unbalance factor according to caused by the negative sequence voltage and the negative-sequence current
Degree of unbalancedness carries out positioning to imbalance of three-phase voltage source to be included：Obtain voltage unbalance factor caused by the negative-sequence current and institute
State the ratio of voltage unbalance factor caused by negative sequence voltage；If the ratio is less than or equal to preset value, it is determined that the three-phase
Voltage unbalance source is located at power station side or load side；If the ratio is more than preset value, it is determined that the imbalance of three-phase voltage
Source is located at grid side.
Alternatively, if the voltage unbalance factor exceedes voltage unbalance factor limit value, points of common connection is obtained
Negative-sequence current caused by voltage unbalance factor include：If the voltage unbalance factor exceedes voltage unbalance factor limit value,
Obtain the harmonic content of the points of common connection；If the harmonic content obtains public company not less than harmonic content threshold value
Voltage unbalance factor caused by the negative-sequence current of contact.
Alternatively, before voltage unbalance factor caused by the negative sequence voltage in the acquisition points of common connection, methods described
Also include：Obtain the magnitude of voltage and current value of the points of common connection；The points of common connection is calculated according to the magnitude of voltage
Negative sequence voltage value, and the voltage unbalance factor according to caused by the negative sequence voltage value calculates the negative sequence voltage.
Alternatively, the voltage unbalance factor according to caused by the negative sequence voltage value calculates the negative sequence voltage includes：
Voltage unbalance factor ε is calculated according to below equationU2,
Wherein, U2For the negative sequence voltage value of the points of common connection, ULFor the r.m.s. of the line voltage of the points of common connection
Value.
Alternatively, voltage unbalance factor caused by the negative-sequence current for obtaining points of common connection includes：According to the electricity
Flow valuve calculates the negative sequence current value of the points of common connection, and according to caused by the negative sequence current value calculates the negative-sequence current
Voltage unbalance factor.
Alternatively, the voltage unbalance factor according to caused by the negative sequence current value calculates the negative-sequence current includes：
According to below equation calculating current degree of unbalancedness εI2,
Wherein, I2For the negative sequence current value of the points of common connection, ULFor the r.m.s. of the line voltage of the points of common connection
Value, SdFor the three-phase shortcircuit capacity of points of common connection.
Alternatively, before the magnitude of voltage and current value for obtaining the points of common connection, methods described also includes：It is right
The magnitude of voltage and current value are set time.
Alternatively, if the harmonic content also includes not less than harmonic content threshold value, methods described：Obtain the voltage
Degree of unbalancedness exceedes the duration of voltage unbalance factor limit value, and carries out corresponding three-phase according to the size of the duration
Voltage unbalance is alarmed.
According to another aspect of the present invention, embodiments of the invention also provide a kind of imbalance of three-phase voltage source positioning dress
Put, including：Electric energy quality monitoring module, for obtaining voltage unbalance factor caused by the negative sequence voltage of points of common connection；If
The voltage unbalance factor exceedes voltage unbalance factor limit value, then it is uneven to obtain electric current caused by the negative-sequence current of points of common connection
Weighing apparatus degree；Uneven source locating module, draw for the voltage unbalance factor according to caused by the negative sequence voltage and the negative-sequence current
The voltage unbalance factor risen positions to imbalance of three-phase voltage source.
Alternatively, the uneven source locating module includes：Comparison unit, it is electric caused by the negative-sequence current for obtaining
Press the ratio of voltage unbalance factor caused by degree of unbalancedness and the negative sequence voltage；Positioning unit, if being less than for the ratio
Or equal to preset value, it is determined that the imbalance of three-phase voltage source is located at power station side or load side；If the ratio is more than default
Value, it is determined that the imbalance of three-phase voltage source is located at grid side.
Alternatively, it is characterised in that the electric energy quality monitoring module includes：First acquisition unit, if for described
Voltage unbalance factor exceedes voltage unbalance factor limit value, then obtains the harmonic content of the points of common connection；If the harmonic wave
Content then obtains voltage unbalance factor caused by the negative-sequence current of points of common connection not less than harmonic content threshold value
Alternatively, the electric energy quality monitoring module also includes：Second acquisition unit, for obtaining the points of common connection
Magnitude of voltage and current value；Computing unit, for calculating the negative sequence voltage value of the points of common connection according to the magnitude of voltage, and
The voltage unbalance factor according to caused by the negative sequence voltage value calculates the negative sequence voltage；And/or calculated according to the current value
The negative sequence current value of the points of common connection, and electric current is uneven according to caused by the negative sequence current value calculates the negative-sequence current
Weighing apparatus degree.
Alternatively, described device also includes：Pair when module, for being set time to the magnitude of voltage and the current value.
Alternatively, described device also includes：Alarm module, if for the harmonic content not less than harmonic content threshold
Value, then the duration that the voltage unbalance factor exceedes voltage unbalance factor limit value is obtained, and according to the duration
Size carries out corresponding imbalance of three-phase voltage alarm.
According to another aspect of the present invention, embodiments of the invention also provide a kind of imbalance of three-phase voltage source positioning system
System, including：Processor, the processor include as above any one imbalance of three-phase voltage source positioner；Display, use
In the result for showing the processor.
Alternatively, the system also includes data-detection apparatus, for detecting the magnitude of voltage and electricity of the points of common connection
Flow valuve is simultaneously sent to the processor, so that the processor carries out imbalance of three-phase voltage source positioning.
Imbalance of three-phase voltage source provided in an embodiment of the present invention localization method, device and system, according to points of common connection
Negative sequence voltage caused by voltage unbalance factor, come judge the points of common connection of power system whether occur three-phase voltage injustice
Weighing apparatus, and when imbalance of three-phase voltage occurs for points of common connection, the voltage unbalance factor according to caused by negative sequence voltage and negative phase-sequence electricity
Relation between voltage unbalance factor caused by stream, to analyze asymmetric impedance or load at points of common connection, and further
It is determined that the orientation in uneven source, can be effectively increased the testing efficiency of imbalance of three-phase voltage, is had with fast positioning imbalance source
Help quickly eliminate imbalance of three-phase voltage, ensure power system stability operation.
Brief description of the drawings
Fig. 1 is the flow chart of the imbalance of three-phase voltage source localization method of embodiments of the invention one；
Fig. 2 is the flow chart of the imbalance of three-phase voltage source localization method of embodiments of the invention two；
Fig. 3 is the structure for the points of common connection that the imbalance of three-phase voltage source localization method of embodiments of the invention two provides
Schematic diagram；
Fig. 4 is the structured flowchart of the imbalance of three-phase voltage source positioner of embodiments of the invention three；
Fig. 5 is the structured flowchart of the imbalance of three-phase voltage source positioner of embodiments of the invention four；
Fig. 6 is the structured flowchart of the imbalance of three-phase voltage source alignment system of embodiments of the invention five.
Embodiment
(identical label represents identical element in some accompanying drawings) is to the three-phase of the embodiment of the present invention below in conjunction with the accompanying drawings
Voltage unbalance source localization method, device and system are described in detail.
Embodiment one
Fig. 1 is the flow chart of the imbalance of three-phase voltage source localization method of embodiments of the invention one, and this method can be used for
Imbalance of three-phase voltage source is positioned in the points of common connection of power system, quickly and easily identifies three-phase voltage not
The position of balanced source, so as to reduce the difficulty of imbalance of three-phase voltage test, help quickly to eliminate imbalance of three-phase voltage, protect
Demonstrate,prove the stability of power system.The imbalance of three-phase voltage source localization method of the embodiment of the present invention, mainly for non-faulting three
Phase voltage imbalance is detected.
In the present embodiment, positioned with the power quality monitoring device of points of common connection to perform the imbalance of three-phase voltage source
Illustrated exemplified by method, but it should be understood by those skilled in the art that in actual applications, arbitrarily with corresponding data acquisition
With the other equipment of processing function, the imbalance of three-phase voltage source localization method that the present embodiment performs the present invention may be referred to.
As shown in figure 1, the imbalance of three-phase voltage source localization method of the present embodiment includes：
S110, obtain voltage unbalance factor caused by the negative sequence voltage of points of common connection.
Because non-equilibrium among three phase voltages are the important indicators of the quality of power supply in measurement power system, and, power system
The negative sequence component of middle voltage and current is the main reason for causing three-phase imbalance, therefore, obtains and is connected altogether in power system public affairs
Voltage unbalance factor caused by the negative sequence voltage of point, can be as judging whether imbalance of three-phase voltage occurs in power system
Parameter.
In the present embodiment, with the booster stations of the new energy power station (wind power station or photo-voltaic power generation station etc.) of power system
As points of common connection, detect and obtain voltage unbalance factor caused by the negative sequence voltage of the points of common connection.In other implementations
In example, points of common connection can be used as by accessing other power stations of power network or the load side of power network output.
S120, if voltage unbalance factor exceedes voltage unbalance factor limit value, obtain the negative-sequence current of points of common connection
Caused voltage unbalance factor.
After voltage unbalance factor caused by the negative sequence voltage of points of common connection is obtained, enter with voltage unbalance factor limit value
Row compares, if voltage unbalance factor caused by negative sequence voltage exceedes voltage unbalance factor limit value, it is determined that points of common connection occurs
Imbalance of three-phase voltage, voltage unbalance factor caused by the negative-sequence current of points of common connection can be obtained, examine in next step
Survey.
Wherein, voltage unbalance factor limit value can determine according to standard GB/T/T 15543-2008.Standard GB/T/T
15543-2008《Quality of power supply imbalance of three-phase voltage》In formulated the following rules on imbalance of three-phase voltage：
4.1 power system points of common connection voltage unbalance factor permissible values are：During power network normal operation, negative sequence voltage is uneven
Weighing apparatus degree is no more than 2%, and 4% is no more than when short-circuit.
The 4.2 each users for being connected to points of common connection cause this negative sequence voltage degree of unbalancedness permissible value to be generally 1.3%,
It is no more than 2.6% when short-circuit.According to the load condition of tie point and neighbouring generator, relay protection and automatics safe operation
It is required that the permissible value can suitably change, but it must is fulfilled for 4.1 regulation.
In the present embodiment, voltage unbalance factor limit value is set as 1.3%.In other embodiments, voltage unbalance factor limits
Value can be adjusted according to the concrete condition of points of common connection, to be accurately detected whether points of common connection occurs three-phase
Voltage unbalance.
S130, voltage unbalance factor is to three-phase caused by the voltage unbalance factor according to caused by negative sequence voltage and negative-sequence current
Voltage unbalance source is positioned.
The main reason for causing non-faulting imbalance of three-phase voltage is that three phase of impedance are asymmetric or three-phase load is asymmetric,
It is mainly shown as that negative sequence voltage and negative-sequence current cause to damage to electrical equipment in power system.This programme is on this basis, sharp
With the relation between the voltage unbalance factor of the negative sequence voltage of points of common connection and the voltage unbalance factor of negative-sequence current, to determine
Three phase of impedance asymmetry or the asymmetric position of three-phase load in points of common connection, and then to causing imbalance of three-phase voltage to be disturbed
Dynamic source is positioned.
The imbalance of three-phase voltage source localization method of the embodiment of the present invention, suitable for non-faulting imbalance of three-phase voltage
Detected.The method that uneven source is positioned relative to multi-point sampler in the prior art, the localization method of the present embodiment can be with
When imbalance of three-phase voltage occurs for points of common connection, imbalance of three-phase voltage source is quickly located, is reduced to three-phase voltage not
The difficulty of test of balance, it is convenient to take processing in time to eliminate uneven source, and can be actively to prevent imbalance of three-phase voltage
Foundation is provided, ensures the stability and security reliability of power system.
The imbalance of three-phase voltage source localization method of the embodiment of the present invention, by the points of common connection for obtaining power system
Voltage unbalance factor caused by negative sequence voltage, to judge whether points of common connection occurs imbalance of three-phase voltage, and in public company
When contact is in the state of imbalance of three-phase voltage, caused by the voltage unbalance factor according to caused by negative sequence voltage and negative-sequence current
Relation between voltage unbalance factor, the orientation in uneven source is further determined that, effectively increase the survey of imbalance of three-phase voltage
Efficiency is tried, helps quickly to eliminate imbalance of three-phase voltage, ensures power system stability operation.
Embodiment two
Fig. 2 is the flow chart of the imbalance of three-phase voltage source localization method of embodiments of the invention two, and the three-phase voltage is not
Balanced source localization method, suitable for being detected to non-faulting imbalance of three-phase voltage.As shown in Fig. 2 the three-phase voltage is not
Balanced source localization method includes：
S210, the magnitude of voltage and current value of points of common connection are obtained, calculate the negative sequence voltage value and negative phase-sequence of points of common connection
Current value, and calculate voltage unbalance factor caused by voltage unbalance factor caused by negative sequence voltage and negative-sequence current.
In the present embodiment, the booster stations for choosing wind power station access power network are points of common connection, and electricity is detected in power station side
Pressure value and current value, obtain the magnitude of voltage detected and current value magnitude of voltage and current value respectively as points of common connection.When
So, in other embodiments, it can also come in grid side or the load side of points of common connection, detect the voltage of points of common connection
Value and current value.
In practical application scene, as shown in figure 3, the Bulk Supply Substation transformer both sides of booster stations are respectively 220kV high pressures
Side and 35kV low-pressure sides, voltage transformer summation current transformer can be set in 35kV low-pressure sides or 220kV high-pressure sides, to detect
The magnitude of voltage and current value of booster stations.Also, it is preferred that detected in 220kV high-pressure sides, because 220kV buses access power network
Position conveniently sets voltage transformer summation current transformer, and avoids and carry out multiple spot detection and statistics meter in 35kV low-pressure sides
The tedious works such as calculation.
The power quality monitoring device acquisition voltage transformer summation current transformer of booster stations detects commonly connected in real time
Point voltage and current is simultaneously sampled to it, and to ensure the homeostasis per cycle sampled point, lock is used in power quality monitoring device
The software or hardware module of phase ring principle are tracked to system frequency, and then ensure the imbalance of three-phase voltage source of the present embodiment
The reliability of localization method.
Alternatively, before the magnitude of voltage and current value of points of common connection is obtained, by the magnitude of voltage detected and current value
Set time, magnitude of voltage and current value after being alignd using markers calculates negative sequence voltage value and negative sequence current value respectively, to carry
The accuracy of high imbalance of three-phase voltage test.Specifically, can be integrated in power quality monitoring device has time adjustment function
Module, or, using pair when equipment (such as system at GPS pairs) with voltage transformer summation current transformer communicate to connect, it is right
The magnitude of voltage and current value detected is set time.
After power quality monitoring device gets the magnitude of voltage and current value of points of common connection, respectively according to the electricity of detection
Pressure value and current value calculate the negative sequence voltage value and negative sequence current value of points of common connection.Specifically, the magnitude of voltage and electricity detected
Flow valuve is centrifugal pump, and the vector value of fundamental wave and each harmonic is obtained after discrete Fourier transform is carried out, further with pair
Weigh and can obtain negative sequence component, calculate the negative sequence voltage value and negative sequence current value of points of common connection.
After the negative sequence voltage value of points of common connection and negative sequence current value is obtained, respectively according to negative sequence voltage value and negative phase-sequence electricity
Flow valuve calculates voltage unbalance factor caused by negative sequence voltage, and voltage unbalance factor caused by negative-sequence current.
In the present embodiment, according to formula：
With
To calculate negative sequence voltage U respectively2Caused voltage unbalance factor εU2, and negative-sequence current I2Caused Voltage unbalance
Spend εI2.Wherein, negative sequence voltage U2Unit be kV, negative-sequence current I2Unit be A, ULFor the line voltage of the points of common connection
Root-mean-square valve, unit kV can be using value as the average value of the three line voltage virtual values detected；SdFor points of common connection
Three-phase shortcircuit capacity, unit MVA, can be obtained from correlation technique such as correlation engineering design document.Illustrate herein, it is above-mentioned
The imbalance of three-phase voltage source positioning that booster stations of the unit of each parameter in wind power station suitable for the present embodiment are carried out.
In other embodiment, when the positioning of imbalance of three-phase voltage source is carried out to other kinds of points of common connection, if line voltage grade,
Capacity of short circuit grade changes, and can adjust the unit of each parameter, and above-mentioned two formula is adjusted accordingly.
In addition, the voltage value data of voltage transformer detection, the electric current Value Data of current transformer detection, and electric energy matter
Negative sequence voltage Value Data, negative-sequence current Value Data and Voltage unbalance degrees of data that monitoring device calculates are measured, phase can be sent to
Stored in the data storage answered, for relevant treatment or subsequent analysis.
What deserves to be explained is it is uneven that voltage caused by the negative sequence voltage and negative-sequence current of points of common connection is calculated in this programme
The method not limited to this of weighing apparatus degree, the method that can arbitrarily calculate voltage unbalance factor caused by negative sequence voltage and negative-sequence current,
Can be with the imbalance of three-phase voltage source localization method of the present embodiment, in the range of the restriction of the application.
Equipped with a variety of electric protective equipments (for example, protective relaying device) in power system.Power quality monitoring device
Sample frequency, and calculate the calculating frequency of voltage unbalance factor caused by negative sequence voltage and negative-sequence current, can with it is electric
Protection equipment is identical or lower slightly, thus can be effectively prevented from the larger amount of calculation that frequently detection voltage unbalance factor is brought, from
And reduce the cpu load of power quality monitoring device.
S220, obtain voltage unbalance factor caused by the negative sequence voltage of points of common connection.
In the present embodiment, after power quality monitoring device calculates voltage unbalance factor caused by negative sequence voltage, according to public
Voltage unbalance factor caused by the negative sequence voltage of tie point, it can judge whether points of common connection occurs three-phase voltage not exactly
Balance.
S230, if voltage unbalance factor exceedes voltage unbalance factor limit value, obtain the harmonic content of points of common connection.
If voltage unbalance factor caused by the negative sequence voltage obtained exceedes voltage unbalance factor limit value, it is determined that public company
Imbalance of three-phase voltage occurs for contact.Now, the harmonic content detection of points of common connection is carried out, for determining three-phase voltage injustice
Whether weighing apparatus is caused by harmonic wave causes voltage waveform distortion.
S240, if caused by the negative-sequence current that harmonic content not less than harmonic content threshold value, obtains points of common connection
Voltage unbalance factor.
For example, harmonic content data are obtained from harmonic detecting equipment, if harmonic content exceedes harmonic content threshold value,
Determine that the imbalance of three-phase voltage that points of common connection occurs is caused by harmonic wave, can be alarmed, staff is taken in time
Processing carrys out harmonic carcellation.Wherein, harmonic content threshold value can be according to standard GB/T/T 14549-1993《The quality of power supply is public
Mains by harmonics》It is determined that.
If harmonic content is not less than harmonic content threshold value, it is determined that the imbalance of three-phase voltage that points of common connection occurs is not
It is to be caused by harmonic wave, voltage unbalance factor caused by the negative-sequence current of points of common connection can be obtained and carry out next step detection.
Preferably, points of common connection harmonic content not less than harmonic content threshold value in the case of, it is uneven to obtain voltage
Weighing apparatus degree exceedes the duration of voltage unbalance factor limit value, and carries out corresponding three-phase voltage injustice according to the size of duration
Weighing apparatus alarm.That is, it is determined that imbalance of three-phase voltage not caused by harmonic wave after, continued according to imbalance of three-phase voltage
The length of time carries out different grades of alarm, facilitates staff to take corresponding processing mode.
For example, four preset duration scopes are set：0.5 to 30 cycle, 30 cycles to 3s, 3s to 1min, more than 1min (its
In, cycle can determine according to power system design parameter, for example, it is 20ms that 50Hz systems, which correspond to cycle).Detecting three-phase
When the duration of Voltage unbalance is in the range of this four preset durations, instantaneous imbalance of three-phase voltage report is carried out respectively
Imbalance of three-phase voltage is alarmed when alert, temporary transient imbalance of three-phase voltage is alarmed, imbalance of three-phase voltage is alarmed and be long in short-term.
It should be noted that the step of imbalance of three-phase voltage mentioned here alarm, can before step S240 or
Perform, can also be performed parallel with step S240 afterwards.
S250, the ratio of voltage unbalance factor caused by the voltage unbalance factor according to caused by negative-sequence current and negative sequence voltage
Imbalance of three-phase voltage source is positioned.
Specifically, the ratio of voltage unbalance factor caused by voltage unbalance factor caused by negative-sequence current and negative sequence voltage is obtained
Value, and the ratio is contrasted with preset value, the orientation in imbalance of three-phase voltage source is determined according to comparing result.Wherein, in advance
If value and the concrete condition and engineering experience value of points of common connection determine, for example, with the boosting of wind power station in the present embodiment
Stand as points of common connection, then preset value can determine according to the operational factor of each electrical equipment and circuit in booster stations.This implementation
In example, preset value 0.65.
If the ratio is more than preset value, it is determined that imbalance of three-phase voltage source is located at grid side；If the ratio is less than or waited
In preset value, it is determined that imbalance of three-phase voltage source is located at power station side or load side.Wherein, power station side is the wind-force of access power network
The input of the power networks such as power station, photo-voltaic power generation station, load side are the output of the power networks such as the industrial area of access power network, living area
End.
Points of common connection occur imbalance of three-phase voltage when, can the voltage unbalance factor according to caused by negative-sequence current and
The ratio of voltage unbalance factor caused by negative sequence voltage positions uneven source, is not required to that by complexity analysis three-phase can be determined in time
The orientation in Voltage unbalance source, reduce imbalance of three-phase voltage difficulty of test, improve testing efficiency.Such as, however, it is determined that it is uneven
Source is located at load side, and whether the impedance that transmission line of electricity can be directly carried out in the load side of points of common connection symmetrically waits detection, with
It is determined that the exact position in uneven source and carrying out timely processing.
The imbalance of three-phase voltage source localization method of the embodiment of the present invention, further shows on the basis of above-described embodiment one
Go out in points of common connection collection voltages value and current value, to calculate voltage unbalance factor caused by negative sequence voltage and negative-sequence current
Mode, can more be accurately determined whether points of common connection occurs imbalance of three-phase voltage；And further illustrate root
According to the ratio of voltage unbalance factor caused by voltage unbalance factor caused by negative-sequence current and negative sequence voltage, to determine three-phase voltage
The method in the orientation in uneven source, the orientation in imbalance of three-phase voltage source can be distinguished exactly, reduce imbalance of three-phase voltage
Difficulty of test；And the mode alarmed according to the duration of imbalance of three-phase voltage is further increased, conveniently adopt
Different processing modes is taken to eliminate uneven source, ensures the stability and security reliability of power system.
Embodiment three
Fig. 4 is the structured flowchart of the imbalance of three-phase voltage source positioner of embodiments of the invention three, and the device is used for
Perform the method and step of above-described embodiment one.As shown in figure 4, the imbalance of three-phase voltage source positioner is supervised including the quality of power supply
Survey module 410 and uneven source locating module 420.
Wherein：Electric energy quality monitoring module 410 is used to obtain Voltage unbalance caused by the negative sequence voltage of points of common connection
Degree；If voltage unbalance factor exceedes voltage unbalance factor limit value, electric current caused by the negative-sequence current of points of common connection is obtained
Degree of unbalancedness；Uneven source locating module 420 is used for the voltage unbalance factor according to caused by negative sequence voltage and negative-sequence current causes
Voltage unbalance factor imbalance of three-phase voltage source is positioned.
The imbalance of three-phase voltage source positioner of the embodiment of the present invention, according to caused by the negative sequence voltage of points of common connection
Voltage unbalance factor, to judge whether points of common connection occurs imbalance of three-phase voltage, and exceed limit value in voltage unbalance factor
When determine that points of common connection is in the state of imbalance of three-phase voltage, the further voltage unbalance factor according to caused by negative sequence voltage
With negative-sequence current caused by voltage unbalance factor determine the orientation in uneven source, so as to effectively increasing imbalance of three-phase voltage
Testing efficiency, help quickly to eliminate imbalance of three-phase voltage, ensure power system stability operation.
Example IV
The structured flowchart of the imbalance of three-phase voltage source positioner of Fig. 5 embodiments of the invention four, the positioner can
It is considered as a kind of optional implementation of the positioner based on above-described embodiment three, available for the three-phase for performing above-described embodiment two
Voltage unbalance source localization method.
As shown in figure 5, above-mentioned uneven source locating module 420 includes comparison unit 421 and positioning unit 422, contrast is single
Member 421 is used for the ratio for obtaining voltage unbalance factor caused by voltage unbalance factor caused by negative-sequence current and negative sequence voltage；It is fixed
If bit location 422 is less than or equal to preset value for ratio, it is determined that imbalance of three-phase voltage source is located at power station side or load side；
If ratio is more than preset value, it is determined that imbalance of three-phase voltage source is located at grid side.
Alternatively, above-mentioned electric energy quality monitoring module 410 includes first acquisition unit 411, if for Voltage unbalance
Degree exceedes voltage unbalance factor limit value, then obtains the harmonic content of points of common connection；If harmonic content is not less than harmonic content
Threshold value, then obtain voltage unbalance factor caused by the negative-sequence current of points of common connection.
Further, above-mentioned electric energy quality monitoring module 410 also includes second acquisition unit 412 and computing unit 413, the
Two acquiring units 412 are used for the magnitude of voltage and current value for obtaining points of common connection；Computing unit 413 is used to be calculated according to magnitude of voltage
The negative sequence voltage value of points of common connection, and the voltage unbalance factor according to caused by negative sequence voltage calculates negative sequence voltage；And/or root
The negative sequence current value of points of common connection, and the current imbalance according to caused by negative-sequence current calculates negative-sequence current are calculated according to current value
Degree.
Further, said apparatus also include pair when module 430, set time for magnitude of voltage and current value.
Further, said apparatus also includes alarm module 440, if for harmonic content not less than harmonic content threshold
Value, then duration of the harmonic content not less than harmonic content threshold value is obtained, and carried out accordingly according to the size of duration
Imbalance of three-phase voltage is alarmed.
The imbalance of three-phase voltage source positioner of the embodiment of the present invention, in points of common connection collection voltages value and electric current
Value, to calculate voltage unbalance factor caused by negative sequence voltage and negative-sequence current, can be accurately determined whether points of common connection is sent out
Raw imbalance of three-phase voltage；Voltage unbalance factor caused by the voltage unbalance factor according to caused by negative-sequence current and negative sequence voltage
Ratio, to determine the orientation in imbalance of three-phase voltage source, the orientation in imbalance of three-phase voltage source is accurately determined, reduces three-phase electricity
Press unbalanced difficulty of test；And alarmed according to the duration of imbalance of three-phase voltage, conveniently take different places
Reason mode eliminates uneven source, ensures the stability and security reliability of power system.
Embodiment five
Fig. 6 is the structured flowchart of the imbalance of three-phase voltage source alignment system of embodiments of the invention five.As shown in fig. 6,
The three-phase imbalance source alignment system includes processor 610 and display 620, and processor 610 includes above-described embodiment three or real
Apply the imbalance of three-phase voltage source positioner of example four；Display 620, the result for video-stream processor 610.
In the present embodiment, the system can also include data-detection apparatus 630, memory 640 or communication controler 650 etc.
Equipment.
Data-detection apparatus 630 is used to detect the imbalance of three-phase voltage characteristic quantity of points of common connection and is sent to the place
Device is managed, so that the processor carries out imbalance of three-phase voltage source positioning.For example, data-detection apparatus 630 can be that voltage is mutual
Sensor summation current transformer, it is respectively used to the magnitude of voltage and current value of detection points of common connection in real time.
Memory 640 can be the database set at points of common connection, be set for storing processor 610 and Data Detection
Standby 630 data sent in the positioning process of imbalance of three-phase voltage source, for example, what data-detection apparatus 630 detected
The magnitude of voltage and current value of points of common connection, or the negative sequence voltage value of points of common connection or negative that processor 610 is calculated
Sequence current value, and voltage unbalance factor caused by negative sequence voltage value or negative sequence current value.
Communication controler 650 is used to transmit data between each equipment, for example, data-detection apparatus 630 is detected
Characteristic quantity data are sent to processor 610 or memory 640, and the negative sequence voltage value transmission of data that processor 640 is sent passes
It is defeated to arrive memory 640 etc..
Further, equipment 660 when the system also includes pair, has time adjustment function for integrated in memory 640
Module when, it is uneven that the three-phase voltage of points of common connection that data-detection apparatus 630 detects is received by communication controler 650
Weighing apparatus characteristic quantity data are set time, and by markers to its imbalance of three-phase voltage characteristic quantity data by communication controler 650,
It is transferred to processor 610 and carries out the processing of imbalance of three-phase voltage detection, or is transferred to memory 640 and is stored.Specifically
Ground, pair when equipment 660 can be GPS pairs when system.
The system can be used for performing above-described embodiment one or the imbalance of three-phase voltage source localization method of embodiment two, in electricity
When imbalance of three-phase voltage occurring in Force system, the orientation in uneven source is quickly determined, it is convenient to eliminate imbalance of three-phase voltage,
It is favorably improved the stability of power system.
It may be noted that according to the needs of implementation, all parts/step described in this application can be split as more multi-section
Part/step, the part operation of two or more components/steps or components/steps can be also combined into new components/steps,
To realize the purpose of the present invention.
The foregoing is only a specific embodiment of the invention, but protection scope of the present invention is not limited thereto, any
Those familiar with the art the invention discloses technical scope in, change or replacement can be readily occurred in, should all be contained
Cover within protection scope of the present invention.Therefore, protection scope of the present invention should be based on the protection scope of the described claims.
Claims (17)
- A kind of 1. imbalance of three-phase voltage source localization method, it is characterised in that including：Obtain voltage unbalance factor caused by the negative sequence voltage of points of common connection；If the voltage unbalance factor exceedes voltage unbalance factor limit value, caused by the negative-sequence current for obtaining points of common connection Voltage unbalance factor；According to voltage unbalance factor caused by voltage unbalance factor caused by the negative sequence voltage and the negative-sequence current to three-phase Voltage unbalance source is positioned.
- 2. according to the method for claim 1, it is characterised in that the Voltage unbalance according to caused by the negative sequence voltage Voltage unbalance factor caused by degree and the negative-sequence current carries out positioning to imbalance of three-phase voltage source to be included：Obtain the ratio of voltage unbalance factor caused by voltage unbalance factor caused by the negative-sequence current and the negative sequence voltage；If the ratio is less than or equal to preset value, it is determined that the imbalance of three-phase voltage source is located at power station side or load side；If the ratio is more than preset value, it is determined that the imbalance of three-phase voltage source is located at grid side.
- 3. method according to claim 1 or 2, it is characterised in that if the voltage unbalance factor exceedes voltage Degree of unbalancedness limit value, then obtain points of common connection negative-sequence current caused by voltage unbalance factor include：If the voltage unbalance factor exceedes voltage unbalance factor limit value, the harmonic content of the points of common connection is obtained；If the harmonic content obtains voltage caused by the negative-sequence current of points of common connection not less than harmonic content threshold value The degree of balance.
- 4. according to the method for claim 1, it is characterised in that caused by the negative sequence voltage in the acquisition points of common connection Before voltage unbalance factor, methods described also includes：Obtain the magnitude of voltage and current value of the points of common connection；The negative sequence voltage value of the points of common connection is calculated according to the magnitude of voltage, and according to calculating the negative sequence voltage value Voltage unbalance factor caused by negative sequence voltage.
- 5. according to the method for claim 4, it is characterised in that described that the negative phase-sequence electricity is calculated according to the negative sequence voltage value Voltage unbalance factor includes caused by pressure：Voltage unbalance factor ε is calculated according to below equationU2,<mrow> <msub> <mi>&epsiv;</mi> <mrow> <mi>U</mi> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mfrac> <mrow> <mn>100</mn> <msub> <mi>U</mi> <mn>2</mn> </msub> </mrow> <msub> <mi>U</mi> <mi>L</mi> </msub> </mfrac> <mi>%</mi> </mrow>Wherein, U2For the negative sequence voltage value of the points of common connection, ULFor the root-mean-square valve of the line voltage of the points of common connection.
- 6. according to the method for claim 4, it is characterised in that electricity caused by the negative-sequence current for obtaining points of common connection Pressure degree of unbalancedness includes：The negative sequence current value of the points of common connection is calculated according to the current value, and according to calculating the negative sequence current value Voltage unbalance factor caused by negative-sequence current.
- 7. according to the method for claim 6, it is characterised in that described that the negative phase-sequence electricity is calculated according to the negative sequence current value Voltage unbalance factor includes caused by stream：According to below equation calculating current degree of unbalancedness εI2,<mrow> <msub> <mi>&epsiv;</mi> <mrow> <mi>I</mi> <mn>2</mn> </mrow> </msub> <mo>=</mo> <mfrac> <mrow> <msqrt> <mn>3</mn> </msqrt> <msub> <mi>I</mi> <mn>2</mn> </msub> <msub> <mi>U</mi> <mi>L</mi> </msub> </mrow> <mrow> <mn>10</mn> <msub> <mi>S</mi> <mi>d</mi> </msub> </mrow> </mfrac> <mi>%</mi> </mrow>Wherein, I2For the negative sequence current value of the points of common connection, ULFor the root-mean-square valve of the line voltage of the points of common connection, SdFor the three-phase shortcircuit capacity of points of common connection.
- 8. according to the method for claim 3, it is characterised in that in the magnitude of voltage and electricity for obtaining the points of common connection Before flow valuve, methods described also includes：The magnitude of voltage and current value are set time.
- 9. according to the method for claim 3, it is characterised in that if the harmonic content not less than harmonic content threshold value, Methods described also includes：The duration that the voltage unbalance factor exceedes voltage unbalance factor limit value is obtained, and according to the big of the duration It is small to carry out corresponding imbalance of three-phase voltage alarm.
- A kind of 10. imbalance of three-phase voltage source positioner, it is characterised in that including：Electric energy quality monitoring module, for obtaining voltage unbalance factor caused by the negative sequence voltage of points of common connection；It is if described Voltage unbalance factor exceedes voltage unbalance factor limit value, then obtains current imbalance caused by the negative-sequence current of points of common connection Degree；Uneven source locating module, cause for the voltage unbalance factor according to caused by the negative sequence voltage and the negative-sequence current Voltage unbalance factor imbalance of three-phase voltage source is positioned.
- 11. device according to claim 10, it is characterised in that the uneven source locating module includes：Comparison unit, for obtaining voltage caused by voltage unbalance factor caused by the negative-sequence current and the negative sequence voltage not The ratio of the degree of balance；Positioning unit, if being less than or equal to preset value for the ratio, it is determined that the imbalance of three-phase voltage source is positioned at electricity Stand side or load side；If the ratio is more than preset value, it is determined that the imbalance of three-phase voltage source is located at grid side.
- 12. the device according to claim 10 or 11, it is characterised in that the electric energy quality monitoring module includes：First acquisition unit, if exceeding voltage unbalance factor limit value for the voltage unbalance factor, obtain described public The harmonic content of tie point；If the harmonic content, not less than harmonic content threshold value, the negative phase-sequence for obtaining points of common connection is electric Voltage unbalance factor caused by stream.
- 13. device according to claim 12, it is characterised in that the electric energy quality monitoring module also includes：Second acquisition unit, for obtaining the magnitude of voltage and current value of the points of common connection；Computing unit, for calculating the negative sequence voltage value of the points of common connection according to the magnitude of voltage, and according to the negative phase-sequence Magnitude of voltage calculates voltage unbalance factor caused by the negative sequence voltage；And/or calculated according to the current value described commonly connected The negative sequence current value of point, and the current unbalance factor according to caused by the negative sequence current value calculates the negative-sequence current.
- 14. device according to claim 12, it is characterised in that described device also includes：Pair when module, for being set time to the magnitude of voltage and the current value.
- 15. device according to claim 12, it is characterised in that described device also includes：Alarm module, if obtaining the voltage unbalance factor not less than harmonic content threshold value for the harmonic content and surpassing The duration of overvoltage degree of unbalancedness limit value, and corresponding imbalance of three-phase voltage is carried out according to the size of the duration Alarm.
- A kind of 16. imbalance of three-phase voltage source alignment system, it is characterised in that including：Processor, the processor include the imbalance of three-phase voltage source positioning dress as any one of claim 10 to 15 Put；Display, for showing the result of the processor.
- 17. according to the system described in claim 16, it is characterised in that the system also includes data-detection apparatus, is used for Detect the magnitude of voltage of the points of common connection and current value and be sent to the processor, so that the processor carries out three-phase electricity Uneven source is pressed to position.
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